On Three new rarasit'ic Acar'i. 4)U 



irregular in form, 1 aboral, modified furrow spinelet, and 1 

 suboral pointed spine ; in interbrachium the first pair o£ 

 adjacent adanibulacral plates touch or join only at their 

 proximal ends — are not fused the whole extent of their 

 external or lateral faces, nor is there directly above them a 

 prominent pair of first marginal plates as in Brisinga and 

 Freiiella, and allies. 



Type-localiU/. — 'Albatross' station 2859, off British 

 Columbia (55° 20' N., 13G" 20' W.j, 1569 fathoms, grey 

 ooze, bottom temperature, 34°*9 Fahrenheit. 



LII. — On Three new Parasitic Acari. 

 Y^y Stanley Hirst. 



(Published by permission of the Trustees of tlie British Museum.) 



Family Listrophoridae. 



The curious new mite briefly described below lives on the 

 guinea-pig, being found on the hairs of the posterior part of 

 the back. It is a minute species, and this is no doubt the 

 reason why it has hitherto escaped notice. The mite clasps 

 a hair of the host with its anterior legs, which are speciall}' 

 modified for this purpose. During copulation the male 

 attaches himself to the generative nymph by the little suckers 

 on the venter and also by the elongated legs of the fourth 

 pair, the hook of the tarsus becoming fixed in the projecting 

 ])osterior margin of the second epimeron. Whilst copulating 

 the heads of both male and nymph point in the same direction, 

 instead of in opposite directions as in the genus Scldzocarpus. 



Chieodiscoides, gen. nov. 



Anterior legs modified so as to form clasping-organs as in 

 ChirodisGus, Trouess. & Nn., but a small pulviihis is present 

 on the tarsi of these limbs. Fourth leg of male longer than 

 the others, and its tarsus is bent at the end to form a hook. 

 Body of the male not bifid at the end as is the case in Ghiro- 

 discus, but produced into a short unpaired process. There 

 are no long hairs on the body. 



Chirodiscoides cavice, sp. n. 

 Body of ovigerous female narrow and elongated, being 



